1. Field of the Invention
The present invention relates to a network printer and a method of transmitting data by the network printer, and more particularly, to a wireless local area network (LAN) card having an access point function, a network printer having the LAN card, and a method of transmitting data by the network printer via wire/wireless transmission.
2. Description of the Related Art
A wireless local area network (LAN), which adopts the standard protocol, IEEE 802.11b, creates a network with wireless network devices, such as a desktop computer, a lap top computer, and a wireless network printer, with a 100-meter radius (a radius of 30 meters in an office with a number of interfering objects), using a radio frequency of 2.4 GHz.
FIG. 1 is a view of a conventional wireless network printing system that includes a cable LAN 20, an access point 30 that is typically electrically connected to the cable LAN 20, wireless clients 40 and 50, and a printer 60.
Each of the wireless clients 40 and 50 and the printer 60 includes a wireless LAN card that transmits/receives predetermined data by radio. The access point 30 is a fixed (stationary) unit that functions as a hub between the wireless clients 40 and 50 and the printer 60 each of which includes the wireless LAN card.
In case of short unobstructed distances among the wireless printer 60 and the wireless clients 40 or 50, the wireless printer 60 having the wireless LAN card can receive printing data directly from the wireless LAN card of the wireless client 40 or 50 and output the data. Because a repeater, such as the access point 30, is not used in this case, the distance between the printer 60 and the wireless client 40 or 50 becomes shorter. Therefore, the conventional wireless network printing system is able to transmit printing data when there is no obstacle between the printer 60 and the wireless client 50.
On the contrary, if the distance among the printer 60 and the wireless client 40 or 50 becomes long and there is an obstacle between the printer 60 and the wireless client 40 or 50, the access point 30 having a repeating function is inevitably required. In the event that the printer 60 having a wireless LAN card is installed in a large office having many obstacles between the printer 60 and the wireless client 40 or 50, the printer 60 receives printing data from the wireless LAN card of the wireless client 40 or 50 via the access point 30 and prints the printing data. However, in this case, the access point 30 is fixed at a certain point in the office, and thus, a plurality of access points are required to accommodate wireless communication among the wireless printer 60 and the wireless clients 40 or 50 outside of a communication range of a given access point 30.